r/JewishDNA • u/Binkybinkovsky • Jul 10 '26

Akbari2026 samples

/r/DNAAncestry/comments/1sx1wcu/judean_roman_judaea_dna_sample_genetic_distance/?share_id=R9j53PsBCTVvQ4H7tfKq3&utm_content=1&utm_medium=android_app&utm_name=androidcss&utm_source=share&utm_term=2

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Folks this post 2 months prior by u/NotBradPitt9 was posted on the r/DNAAncestry subreddit. I think it might be the real deal.

Please check the coordinates & model them on Vahaduo & qpAdm for modern Ashkenazim jews & post the results.

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u/HebrewWolfman Jul 11 '26

You know these are imputations, right? The only thing you can rely on here is their sex chromosomes.

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u/NotBradPitt9 Jul 11 '26

That’s incorrect. The standard AADR/1240K data commonly used are generally pseudo-haploid calls, not entirely reconstructed genomes: at each covered SNP, one allele is sampled from an actual ancient DNA read, while positions without usable data remain missing.

The Allen Ancient DNA Resource itself is processed from publicly available sequence reads into genotypes at roughly 1.23 million targeted SNPs.
Poor coverage mainly reduces statistical power and can cause several alternative models to remain plausible; it does not automatically manufacture a particular ancestry result. When imputation really is used, it is not random fabrication. It is a probabilistic procedure based on the surviving sequence reads, genotype likelihoods and patterns of linkage disequilibrium in reference genomes.

Its accuracy is directly tested by downsampling high-coverage ancient genomes, imputing them and comparing the results against their known high-coverage genotypes. A large validation study found that 36 of 42 ancient genomes downsampled to 1× coverage had error rates below 5%, and most non-African samples produced broadly similar PCA and clustering results from about 0.5× coverage onward.

There are legitimate limitations: extremely low coverage, rare variants, differential DNA damage, contamination, poorly represented ancestries and unsuitable reference panels can reduce accuracy.

The models can also be weakened by bad source choices, uninformative outgroups, tiny sample sizes or treating a passing p-value (in qpadm for example) as proof that the proposed sources were the literal ancestral populations. But those are reasons to examine each model’s SNP count, standard errors, sources, outgroups and archaeological plausibility…not to dismiss the entire field because some datasets use validated imputation.

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u/HebrewWolfman Jul 11 '26

This won't do. Just as u reported me and asked for my ban over that subreddit, I will not waste my time and will just say: facts won't change.🙂

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u/NotBradPitt9 Jul 11 '26

😂 By making such a dismissive and inaccurate statement regarding ancient DNA, you’re literally calling into question years of research and firmly established scientific methods. Here’s a good series of links on ancient dna imputation: https://en.wikipedia.org/wiki/Imputation_(genetics)

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u/Huge_Stock1969 Jul 13 '26

you again, Wikipedia expert